Effects of allergen sensitization on response to therapy in children with eosinophilic esophagitis

Diagnosis and management of eosinophilic esophagitis in children: An update from the European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN)

INTRODUCTION

Eosinophilic esophagitis (EoE) is a chronic inflammatory disease of the esophagus characterized by symptoms of esophageal dysfunction and histologically by predominantly eosinophilic infiltration of the squamous epithelium. European Society for Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) published a guideline in 2014; however, the rapid evolution of knowledge about pathophysiology, diagnostic criteria, and therapeutic options have made an update necessary.

METHODS

A consensus group of pediatric gastroenterologists from the ESPGHAN Working Group on Eosinophilic Gastrointestinal Diseases (ESPGHAN EGID WG) reviewed the recent literature and proposed statements and recommendations on 28 relevant questions about EoE. A comprehensive electronic literature search was performed in MEDLINE, EMBASE, and Cochrane databases from 2014 to 2022. The Grading of Recommendations Assessment, Development and Evaluation system was used to assess the quality of evidence and formulate recommendations.

RESULTS

A total of 52 statements based on the available evidence and 44 consensus-based recommendations are available. A revision of the diagnostic protocol, options for initial drug treatment, and the new concept of simplified empiric elimination diets are now available. Biologics are becoming a part of the potential armamentarium for refractory EoE, and systemic steroids may be considered as the initial treatment for esophageal strictures before esophageal dilation. The importance and assessment of quality of life and a planned transition to adult medical care are new areas addressed in this guideline.

CONCLUSION

Research in recent years has led to a better understanding of childhood EoE. This guideline incorporates the new findings and provides a practical guide for clinicians treating children diagnosed with EoE.

Associations of Eosinophilic Gastrointestinal Disorders with Other Gastrointestinal and Allergic Diseases

Eosinophilic gastrointestinal disorders (EGIDs) are becoming more common causing significant suffering and reduced quality of life. These conditions can affect different parts of the digestive system, either individually or in combination. Recognition of their link to allergic disorders or other gastrointestinal (GI) diseases has raised questions about their shared underlying mechanisms, which has had implications for diagnosis and management. The authors critically examine the current understanding of the connection between EGIDs and allergic conditions (ie, atopic dermatitis, allergic rhinitis, asthma, and food allergy) and GI diseases (ie, inflammatory bowel disease, celiac disease, gastroesophageal reflux disease, and motility disorders).

Clinical Evaluation of the Child with Eosinophilic Esophagitis

The diagnosis of eosinophilic esophagitis (EoE) is based on clinical symptoms of esophageal dysfunction and eosinophil predominant esophageal inflammation. Clinical symptoms in children with EoE vary based on age and may be nonspecific. EoE has a male predominance with the majority having comorbid atopic disorders. At present, treatment options include medications (proton pump inhibition, swallowed topical steroids), dietary therapy or biologic therapy (dupilumab, approved for those ≥12 years of age). Outside of EoE in the context of oral immunotherapy, EoE is typically chronic requiring lifelong therapy. Long-term complications including feeding difficulties, malnutrition, and fibrostenotic disease.

Six-Food Elimination Diet Is Less Effective During Pollen Season in Adults With Eosinophilic Esophagitis Sensitized to Pollens

INTRODUCTION

The role of inhaled and swallowed aeroallergens in treatment outcomes of adult patients with eosinophilic esophagitis (EoE) is unclear. We hypothesized that the pollen season contributes to the failure of the 6-food elimination diet (SFED) in EoE.

METHODS

We compared outcomes of patients with EoE who underwent SFED during vs outside of the pollen season. Consecutive adult patients with EoE who underwent SFED and skin prick test (SPT) for birch and grass pollen were included. Individual pollen sensitization and pollen count data were analyzed to define whether each patient had been assessed during or outside of the pollen season after SFED. All patients had active EoE (≥15 eosinophils/high-power field) before SFED and adhered to the diet under the supervision of a dietitian.

RESULTS

Fifty-eight patients were included, 62.0% had positive SPT for birch and/or grass, whereas 37.9% had negative SPT. Overall, SFED response was 56.9% (95% confidence interval, 44.1%-68.8%). When stratifying response according to whether the assessment had been performed during or outside of the pollen season, patients sensitized to pollens showed significantly lower response to SFED during compared with outside of the pollen season (21.4% vs 77.3%; P = 0.003). In addition, during the pollen season, patients with pollen sensitization had significantly lower response to SFED compared with those without sensitization (21.4% vs 77.8%; P = 0.01).

DISCUSSION

Pollens may have a role in sustaining esophageal eosinophilia in sensitized adults with EoE despite avoidance of trigger foods. The SPT for pollens may identify patients less likely to respond to the diet during the pollen season.

A case of food and aeroallergen sublingual immunotherapy inducing eosinophilic esophagitis

Eosinophilic esophagitis (EoE) has been reported secondary to aeroallergen sublingual immunotherapy (SLIT) and food allergen oral immunotherapy. Gastrointestinal symptoms with food allergen SLIT are uncommon, with no prior reports of cases of food allergen SLIT inducing EoE. Here we report a patient who developed EoE secondary to food and aeroallergen SLIT therapy that resolved with SLIT cessation.

Development of a Practical Guide to Implement and Monitor Diet Therapy for Eosinophilic Esophagitis

Dietary therapy for short- and long-term management of eosinophilic esophagitis is an effective yet poorly understood and underutilized treatment strategy. Despite several prospective trials demonstrating the efficacy of dietary therapies, successful clinical implementation is hampered by the need for a multidisciplinary approach including dietitian support and provider expertise. The availability of these resources is not readily available to most gastroenterologists. Without standardized guidance on starting or completing the diet for gastrointestinal providers and/or consulting dietitians, provider attitudes toward dietary therapy vary greatly depending on familiarity and knowledge gaps in using diet therapy. This review aims to summarize evidence in support of dietary therapy in eosinophilic esophagitis while providing guidance on initiation and implementation of dietary therapy for providers.

Description of allergic phenotype in patients with eosinophilic oesophagitis: management protocol proposal

There is a profile of patient with eosinophilic oesophagitis and atopic background, marked by the existence of IgE-mediated sensitizations. Our aim is to report the observed sensitivities to environmental and food allergens and panallergens in patients with eosinophilic oesophagitis with atopic background as well as characterizing other markers or analytical parameters. We suspect that the prevalence of sensitization to panallergens will be high and this will probably be relevant in terms of the onset and clinical course of the disease. We collated clinical and analytical data from 160 adult patients with a reported diagnosis of eosinophilic oesophagitis. These patients were studied between 1 January 2012 and 31 December 2020. During an initial visit skin tests were performed with full batteries of routine aero-allergens and foodstuffs. Patients were subsequently referred for blood test and determination of specific IgE, blood count and total IgE (in all cases), as well as eosinophilic cation protein and IMMUNOISAC in the centres in which this was available. We were able to detect a broad spectrum of sensitizations to environmental, foodstuffs and panallergens. The most common allergic disease was rhinoconjuntivitis. The sensitizations observed to foodstuffs were atypical for the adult population and were not responsible for manifestations compatible with immediate allergy. An important percentage of patients presented seasonal worsening of choking symptoms. We should be able to identify patients with eosinophilic oesophagitis and atopic background. Identifying this phenomenon would enable giving dietary and environmental recommendations as well as more specific and effective treatments to our patients.

Eosinophilic esophagitis in children: Updates and practical aspects of management for allergists in a non-tertiary care private practice setup

Background: Eosinophilic esophagitis (EoE) is a chronic immune and/or antigen-mediated disease characterized by eosinophilic infiltration of mucosa (≥15 eosinophils per high power field) without any secondary etiology. Non-immunoglobulin E mediated mechanisms predominate in EoE. Objective: This review concentrated on a stepwise approach for the allergist working in non-tertiary care private practice. Methods: A medical literature search that focused on several areas of the latest developments in the diagnosis and management of EoE was conducted. Results: There has been a steady increase in the prevalence and incidence of EoE. Clinical symptoms can vary from dysphagia to failure to thrive, depending on the age at presentation; some children develop adaptive behaviors to compensate for dysphagia, such as food preferences and slow eating. The diagnosis is based on a high index of clinical suspicion and is confirmed with endoscopy with biopsies after ruling out other causes of esophageal eosinophilia. Treatment options may include dietary therapy, pharmacologic therapies, or combination therapy. Therapeutic options may also include endoscopic dilation for stricturing disease. Conclusion: Providers should be aware of recent recommendation changes in the diagnostic workup, the role of skin-prick testing, and role of the proton-pump inhibitor as first-line therapy for EoE. Also, clinicians should be aware of the emerging role of empiric dietary therapy as a preferable therapeutic option when compared with the testing-directed diet and the elemental diet. Furthermore, topical glucocorticoid therapies are available, and new developing therapies are being investigated. Reevaluation of esophageal mucosa with biopsies is required approximately 2 months after therapy for a response and after a change in therapies to confirm continued resolution.

The Role of the Environment in Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) is a chronic immune-mediated disease clinicopathologically characterized by esophageal dysfunction. EoE is characterized by eosinophilic histologic inflammation indistinguishable from other atopic diseases such as asthma, eczema, or allergic rhinitis, which often co-occur in patients with EoE. This suggest a possible shared pathophysiology and triggers in the development of EoE with other atopic conditions. Although the evidence of EoE being linked to exposure to allergenic foods is strong, the connection between EoE and aeroallergens is less understood. In this review, we will discuss clinical, epidemiological, and animal studies that investigate how environmental allergens influence the clinical manifestations of EoE and its seasonality. It is also known that the developing immune system is significantly shaped by early-life exposures, pollution, climate change, and those factors that are known to influence development of asthma. We therefore also describe the evidence for and the gaps in our knowledge of the role of early-life exposures, pollution, and climate change in the development of EoE.

The Role of the Environment in Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) is a chronic, immune-mediated inflammatory disease with incompletely understood pathogenesis. Though disease manifestations were initially ascribed to a delayed reaction to food allergens, emerging evidence suggests that modifiable host factors and environmental allergen exposure may also play critical roles in the pathogenesis and ongoing manifestations of EoE. As with other atopic diseases, lack of early-life exposure to microbial pathogens leads to an immune tolerance defect and reprograms the commensal gut microflora toward a type 2 T helper (Th2) phenotype; the esophageal microbiota, a rich environment consisting of diverse bacterial species, is greatly altered by inflammation. Although multiple early life microbiome-altering factors are associated with EoE development, no causative, direct relationships have been identified. Interestingly, large, cross-sectional analyses of several populations identify an inverse relationship between Helicobacter pylori presence and EoE, likely via virulence factors that downregulate Th2 inflammation, though causality has not been proven. In regard to environmental allergens, some studies support seasonal variation in EoE diagnosis and flares, and EoE can be generated after a large, identifiable aeroallergen exposure. Examples include mouse models of intranasal Aspergillus dosing and following initiation of oral immunotherapy to foods or environmental allergens. Conversely, treatment of allergic rhinoconjunctivitis may improve EoE symptoms, though data is limited to case reports and small series. Unfortunately, biologic therapies for atopic conditions have failed to improve EoE symptoms despite improvement in esophageal eosinophil count, though dupilumab shows promise in ongoing studies. Overall, this chapter shows that EoE pathogenesis is likely multifactorial, and the environment is a key component in our understanding of EoE.

The Role of the Environment in Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) is a chronic, immune-mediated inflammatory disease with incompletely understood pathogenesis. Though disease manifestations were initially ascribed to a delayed reaction to food allergens, emerging evidence suggests that modifiable host factors and environmental allergen exposure may also play critical roles in the pathogenesis and ongoing manifestations of EoE. As with other atopic diseases, lack of early-life exposure to microbial pathogens leads to an immune tolerance defect and reprograms the commensal gut microflora toward a type 2 T helper (Th2) phenotype; the esophageal microbiota, a rich environment consisting of diverse bacterial species, is greatly altered by inflammation. Although multiple early life microbiome-altering factors are associated with EoE development, no causative, direct relationships have been identified. Interestingly, large, cross-sectional analyses of several populations identify an inverse relationship between Helicobacter pylori presence and EoE, likely via virulence factors that downregulate Th2 inflammation, though causality has not been proven. In regard to environmental allergens, some studies support seasonal variation in EoE diagnosis and flares, and EoE can be generated after a large, identifiable aeroallergen exposure. Examples include mouse models of intranasal Aspergillus dosing and following initiation of oral immunotherapy to foods or environmental allergens. Conversely, treatment of allergic rhinoconjunctivitis may improve EoE symptoms, though data is limited to case reports and small series. Unfortunately, biologic therapies for atopic conditions have failed to improve EoE symptoms despite improvement in esophageal eosinophil count, though dupilumab shows promise in ongoing studies. Overall, this chapter shows that EoE pathogenesis is likely multifactorial, and the environment is a key component in our understanding of EoE.

Future therapies for eosinophilic gastrointestinal disorders

OBJECTIVE

To review novel therapeutics in development for treatment of eosinophilic gastrointestinal disorders (EGIDs).

DATA SOURCES

Clinical trial data (clinicaltrials.gov) and literature search on PubMed.

STUDY SELECTIONS

Studies on treatment and clinical trials in EGIDs were included in this review.

RESULTS

During the past decade, significant progress has been made in understanding disease mechanisms in EGIDs. As a result, a variety of novel therapeutics have been developed for treatment of these disorders. Several monoclonal antibodies against targets, including interleukin (IL) 4, IL-5, IL-13, integrins, and siglec-8, have shown promise in early trials. Novel formulations of corticosteroids are also in development.

CONCLUSION

The field of EGID research has advanced rapidly, and disease-modifying therapeutics are closer to clinical application.

Allergies and Eosinophilic Esophagitis-Current Updates for the Pediatric Gastroenterologist

PURPOSE OF REVIEW

The purpose of this article is to review recent developments demonstrating the role of allergies, the utility of allergy testing, and the role of the allergist in eosinophilic esophagitis (EoE) management.

RECENT FINDINGS

The majority of patients with EoE have concurrent atopic disorders including food anaphylaxis, asthma, allergic rhinitis, and eczema. An atopic population likely is at greater risk for EoE. Delayed type hypersensitivity to food antigens is the most common pathogenic mechanism. Aeroallergens and pollen-food cross-reactivity also can trigger EoE. Th2 cell-mediated adaptive and innate immunity in response to epithelial damage occurs via IL-13- and IL-4-producing T cells and innate lymphoid cells. While IgE testing for foods is insufficient to build an elimination diet, IgE-mediated allergy may play a role in EoE severity and clinical course. There is strong evidence that Th2 immunity drives EoE. Optimal EoE management should include elucidating and managing EoE triggers and concurrent atopic diatheses.

Allergic Comorbidity in Eosinophilic Esophagitis: Mechanistic Relevance and Clinical Implications

Allergic eosinophilic esophagitis (EoE) is a chronic, allergen-mediated inflammatory disease of the esophagus, and the most common cause of prolonged dysphagia in children and young adults in the developed world. While initially undistinguished from gastroesophageal reflux disease-associated esophageal eosinophilia, EoE is now recognized as a clinically distinct entity that shares fundamental inflammatory features of other allergic conditions and is similarly increasing in incidence and prevalence. The clinical and epidemiologic associations between EoE and other allergic manifestations are well established. In addition to exaggerated rates of atopic dermatitis, IgE-mediated food allergy, asthma, and allergic rhinitis in EoE patients, each of these allergic manifestations imparts individual and cumulative risk for subsequent EoE diagnosis. As such, EoE may be a member of the "allergic march"-the natural history of allergic manifestations during childhood. Several determinants likely contribute to the relationship between these conditions, including shared genetic, environmental, and immunologic factors. Herein, we present a comprehensive review of allergic comorbidity in EoE. We discuss areas of the genome associated with both EoE and other allergic diseases, including the well-studied variants encoding thymic stromal lymphopoietin and calpain 14, among other "atopic" regions. We summarize ways that environmental factors (such as microbiome-altering pressures and aeroallergen exposure) may predispose to multiple allergic conditions including EoE. Finally, we touch on some fundamental features of type 2 inflammation, and the resulting implications for the development of multiple allergic manifestations. We conclude with an analysis of the "type 2" biologics, and how mechanistic similarities between EoE and the other allergic manifestations have important implications for screening and treatment of the allergic patient.

Clinical and Molecular Factors Associated With Histologic Response to Topical Steroid Treatment in Patients With Eosinophilic Esophagitis

BACKGROUND & AIMS

Few factors have been identified that can be used to predict response of patients with eosinophilic esophagitis (EoE) to topical steroid treatment. We aimed to determine whether baseline clinical, endoscopic, histologic, and molecular features of EoE can be used to predict histologic response.

METHODS

We collected data from 97 patients with EoE, from 2009 through 2015, treated with a topical steroid for 8 weeks; 59 patients had a histologic response to treatment. Baseline clinicopathologic features and gene expression patterns were compared between patients with a histologic response to treatment (<15 eos/hpf) and non-responders (≥15 eos/hpf). We performed sensitivity analyses for alternative histologic response definitions. Multivariate logistic regression was performed to identify predictive factors associated with response to therapy, which were assessed with area under the receiver operator characteristic (AUROC) curves.

RESULTS

Baseline dilation was the only independent predictor of non-response (odds ratio [OR], 0.30; 95% CI, 0.10-0.89). When an alternate response (<1 eos/hpf) and non-response (<50% decrease in baseline eos/hpf) definition was used, independent predictors of response status were age (OR, 1.08; 95% CI, 1.02-1.14), food allergies (OR, 12.95; 95% CI, 2.20-76.15), baseline dilation (OR, 0.17; 95% CI, 0.03-0.88), edema or decreased vascularity (OR, 0.20; 95% CI, 0.04-1.03), and hiatal hernia (OR, 0.07; 95% CI, 0.01-0.66). Using these 5 factors, we developed a predictive model that discriminated complete responders from non-responders with an AUROC of 0.88. Baseline gene expression patterns were not associated with treatment response and did not change with different histologic response thresholds.

CONCLUSIONS

In an analysis of 97 patients with EoE, we found dilation to be the only baseline factor associated with non-response to steroid treatment (<15 eos/hpf). However, a model comprising 5 clinical, endoscopic, and histologic factors identified patients with a complete response (<1 eos/hpf). A baseline gene expression panel was not predictive of treatment response at any threshold.

Does Aeroallergen Sensitization Cause or Contribute to Eosinophilic Esophagitis?

Eosinophilic esophagitis is an atopic disease defined clinically by esophageal symptoms in combination with a dense esophageal eosinophilia. EoE is triggered and maintained by exposure to certain foods and it is known that dietary modification controls symptoms and achieves disease remission. Recently, aeroallergens have been implicated in the pathogenesis of EoE. To examine the role of aeroallergens in EoE, we reviewed the published literature. Sensitization and production of IgE antibodies to foods and aeroallergens in subjects with EoE has been demonstrated. However, the evidence suggests only a minor role for IgE-mediated immune reactions in EoE. There is some evidence to support an association of EoE diagnosis and flares with environmental allergen exposure, and animal studies support the notion that EoE may be induced by exposure to inhalant allergens. Some studies show that newly diagnosed cases of EoE follow a seasonal pollen distribution (summer and spring), but the weight of evidence does not support the seasonal occurrence of diagnosis or worsening of symptoms. Overall, we conclude that the current evidence does not support causality in inhalant allergen exposure and the genesis nor exacerbations of EoE in humans, although there is a possibility that inhalant allergen sensitization could play a modifying role in EoE in the context of cross-reacting food allergens.

Allergic components of eosinophilic esophagitis

Eosinophilic esophagitis (EoE) is a disorder of increasing prevalence worldwide, causing clinical symptoms of vomiting, failure to thrive, and dysphagia and complications of esophageal remodeling with strictures and food impactions. Molecular profiling demonstrates EoE to be an eosinophil-predominant disorder with a TH2 cytokine profile reminiscent of other allergic diseases, such as asthma, allergic rhinitis, and atopic dermatitis. Environmental antigens in the form of foods and aeroallergens induce eosinophil, basophil, mast cell, and T-cell infiltration. Pathogenesis depends on local epithelial immune activation with production of thymic stromal lymphopoietin and eotaxin-3. Complications mirror asthmatic airway pathogenesis, with increases in subepithelial collagen deposition, angiogenesis, and smooth muscle hypertrophy. The removal of instigating antigens, especially foods, causes disease resolution in more than 50% of adults and children. The prevalence of concurrent atopic disorders in patients with EoE and the need to control antigen-specific TH2 inflammation underscore the importance of testing for allergens and treating the entire atopic subject to control the potential interplay between organ-specific allergic responses.

What Is the Relationship Between Eosinophilic Esophagitis (EoE) and Aeroallergens? Implications for Allergen Immunotherapy

PURPOSE OF REVIEW

Observations suggesting that aeroallergens trigger eosinophilic esophagitis (EoE) in a subset of patients raise questions about the implications this finding has on the evaluation and management of patients with EoE, including a potential role for allergen immunotherapy.

RECENT FINDINGS

The majority of studies evaluating the potential role of aeroallergens as provocateurs of EoE have addressed this issue by assessing the seasonal variation in EoE diagnosis and/or symptom onset or worsening, with mixed results. For various reasons, reaching accurate conclusions based on this methodology is potentially fraught with error. In addition, studies examining the even harder to assess role of perennial aeroallergens in triggering EoE are lacking. Although clearly not the majority, there may be a subset of patients with EoE and allergic rhinitis in whom exposure to aeroallergens to which they are sensitized contributes to esophageal eosinophilia either through direct chronic esophageal mucosal contact with pollen allergens or from repetitive exposure of the esophageal mucosa to pollen allergens, mediators, and eosinophils in swallowed nasal secretions. Therefore, evaluation for and optimal treatment of comorbid allergic rhinitis in EoE patients are clearly indicated. Recognition of the potential role of aeroallergens as triggers of EoE also raises the question of whether allergen immunotherapy might be an effective form of EoE treatment. Reports of sublingual immunotherapy (SLIT) inducing EoE support the notion that aeroallergens can trigger EoE, but negate this approach as a potential form of EoE therapy. In fact, the use of SLIT is contraindicated in patients with EoE. The literature regarding the role of subcutaneous immunotherapy (SCIT) in patients with EoE is limited. Current evidence indicates that it should not be typically recommended; however, SCIT might benefit a subset of patients with EoE and uncontrolled allergic rhinitis on conventional therapies in whom SCIT would otherwise be indicated for allergic rhinoconjunctivitis, particularly in those with sensitizations to pollens containing allergens that cross react with food allergens. The purpose of this review is to discuss the current literature examining the role of aeroallergens in triggering EoE with a focus on the potential clinical implications of this finding on managing patients with EoE.

Medical and dietary management of eosinophilic esophagitis

OBJECTIVE

Eosinophilic esophagitis (EoE) is a disease of chronic, allergen-driven, T-helper 2 (Th2) immune-mediated inflammation that progresses to fibrostenosis of the esophagus if left untreated. There are currently no Food and Drug Administration (FDA)-approved drugs for the treatment of EoE. This review focuses on the medical and dietary management of EoE.

DATA SOURCES

Manuscripts on EoE treatments were identified on PubMed.

STUDY SELECTIONS

Original research, randomized control trials, retrospective studies, meta-analyses, case series, and on occasions, case reports of high relevance, were selected and reviewed.

RESULTS

Current treatment strategies available to EoE patients center on monotherapy or combination therapy with dietary modification to exclude antigenic stimulation and topical corticosteroids to control Th2-mediated tissue inflammation and pathologic remodeling. Dilation as a rescue therapy for the narrowed, fibrostenotic, symptomatic esophagus can potentially be avoided with optimal medical and elimination diet therapies. The molecular mechanisms underlying EoE pathogenesis are being unraveled, from which targeted therapies can be developed and evaluated in preclinical and clinical studies. Current clinical research efforts focus on optimization of topical corticosteroid delivery, dosing, frequency, and duration of treatment, either alone or in combination with tailored elimination diet. Preliminary clinical trials with biologics targeting interleukin (IL)-5 and IL-13/IL-4 have been completed.

CONCLUSION

Topical corticosteroid, elimination diet, and dilation are the current treatment modalities for confirmed EoE. The use of proton-pump inhibitors (PPI) is being suggested as a potential regimen to treat EoE, based on evolving understanding of PPI-responsive esophageal eosinophilia (PPI-REE). The complexity of EoE treatment regimens and frequent follow-ups require a multimodal, multi-disciplinary management approach to optimize patient care.